Nickel-free duplex stainless steels

Two kinds of nickel-free duplex stainless steels have been developed in this work. These alloys can be characterized with high strength and toughness, good corrosion resistance and low alloy element cost. In comparison with the commercial DSS with a similar PREN, the experimental DSS have a yield strength roughly 100 MPa higher and an elongation to fracture of about 40%. Micro structural investigations showed that such alloys have a relatively stable austenite content at high temperatures and thus are also expected to have a good weldability. Due to the absence of nickel, the experimental DSS exhibit an excellent resistance to SCC in chloride solutions. Finally, these alloys can be cost-efficient because of the total absence of the expensive element nickel and therefore can find applications where high strength and moderate corrosive resistance are required, for example, as reinforcing bars in the building industry.